Nebulizing drug delivery device with interlock detection and temperature protection

ABSTRACT

The present invention provides a nebulizing device with a housing that includes a mouthpiece module, an intermediate module, and a base module. An aerosol generator is in communication with a fluid. A barrier is disposed between the fluid and a drug solution provided within the housing. A signal transmitter and a signal receiver are carried by the housing. The signal is either initiated or terminated when one of the modules is separated or misaligned from the other modules. The device further includes a variable volume resilient structure disposed in communication with the fluid to provide volumetric relief in the event that the fluid expands.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) fromprovisional U.S. Patent Application No. 60/659,778 filed Mar. 9, 2005the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to drug delivery devices, and, inparticular, to drug delivery devices that utilize an aerosol generatorto nebulize a drug solution.

2. Description of the Related Art

Nebulizers are well known in the art and may comprise a number ofmodules that can be selectively coupled to each other. For example, anelectronics module can be provided for containing device electronics,including an aerosol generator, while an intermediate module may beprovided for containing a pool of drug solution. In such systems,activation of the electronics module when the modules are not securelycoupled may damage device electronics or lead to nebulization of drugsolution into the atmosphere, or cause other problems, thus wasting thevaluable medication.

Some nebulizing devices employ aerosol generators that nebulize a drugsolution by transmitting acoustic waves from an acoustic wave generatorto the drug solution via a fluid. In these known nebulizing devices, thefluid may damage other components within a nebulizing device due tothermal expansion. For example, the fluid may expand due to beingexposed to low temperatures that bring the fluid to, or close to, afreezing point. The fluid will also expand when heated by ultrasonicenergy associated with the acoustic waves passing therethrough. Theseexpansions may damage nebulizing device components adjacent to thefluid, or may even crack the surrounding housing portions

SUMMARY OF THE INVENTION

In accordance with the broad teachings of the invention, one aspect ofthe invention relates to a nebulizing drug delivery device, comprising ahousing having a mouthpiece module, an intermediate module, and a basemodule. An aerosol generator is disposed in the intermediate module andoperates to form nebulized particles from the drug solution that can becommunicated to a user through an outlet of the mouthpiece module. Asignal transmitter and signal receiver are carried by the housing. Thesignal passes from the transmitter to the receiver via a conduit. Thesignal is broken when one of the modules is separated from the other themodules resulting in disabling the aerosol generator when the signal isthe not received by the receiver.

Another aspect of the invention relates to a nebulizing drug deliverydevice, comprising a housing including a first housing assembly and asecond housing assembly. The first housing assembly carries an aerosolgenerator and control electronics that operate the aerosol generator togenerate acoustic waves that are transmitted to a drug solution. Theacoustic waves in the drug solution operate to form nebulized particlesfrom the drug solution. The second housing assembly includes an outletthrough which the nebulized particles are communicated to a user, asignal transmitter carried by the housing, a signal receiver carried bythe housing, and a conduit for transmitting a signal from thetransmitter to the receiver. The conduit extends within the firsthousing assembly and the second housing assembly. The signal isinterrupted when the first housing assembly is separated from the secondhousing assembly to prevent the signal from being received by thereceiver, the aerosol generator is disabled when the signal is notreceived by the receiver.

Another aspect of the invention relates to a nebulizing drug deliverydevice, comprising a housing having an inlet and an outlet, an aerosolgenerator in communication with a fluid, and a barrier between the fluidand the drug solution. The aerosol generator operates to form nebulizedparticles from the drug solution that can be communicated to a userthrough the outlet. The device further includes a variable volumeresilient structure disposed in contact with the wave fluid, theresilient structure being reduced in volume to accommodate expansion ofthe fluid in the event of freezing of the fluid.

These and other objects, features, and characteristics of the presentinvention, as well as the methods of operation and functions of therelated elements of structure and the combination of parts and economiesof manufacture, will become more apparent upon consideration of thefollowing description and the appended claims with reference to theaccompanying drawings, all of which form a part of this specification,wherein like reference numerals designate corresponding parts in thevarious figures. It is to be expressly understood, however, that thedrawings are for the purpose of illustration and description only andare not intended as a definition of the limits of the invention. As usedin the specification and in the claims, the singular form of “a”, “an”,and “the” include plural referents unless the context clearly dictatesotherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

A specific embodiment of the invention is now described with referenceto the accompanying drawings, wherein:

FIG. 1A-1C are perspective and elevational views of the nebulizingdevice according to an embodiment of the invention.

FIG. 2 is an exploded perspective view of the nebulizing device inaccordance with an embodiment of the invention.

FIG. 3 is a cross-sectional view of the nebulizing device shown in FIG.1B, taken along section line 3-3, according to one embodiment of theinvention.

FIGS. 4A and 4B are partial cross-sectional views taken along line 4-4of FIG. 1B which illustrate an air flow through the nebulizing deviceaccording to an embodiment of the invention.

FIG. 5 is a cross-sectional view of the nebulizing device of FIG. 6,taken along cross-section line 5-5 of FIG. 6, in accordance with oneembodiment of the invention.

FIG. 6 is a cross-sectional view of the nebulizing device of FIG. 1Btaken along section line 6-6 of FIG. 1B, in accordance with anembodiment of the invention.

FIG. 7 is a cross-sectional view of the nebulizing device of FIG. 1B,taken along section line 7-7 of FIG. 1B, according to an embodiment ofthe invention.

FIG. 8 illustrates a perspective view of an embodiment of the basemodule of the drug delivery device.

FIGS. 9A-9C illustrate front, back, and top elevation views of anembodiment of the base module of the drug delivery device.

FIG. 10 is an exploded perspective view of the base module of the drugdelivery device, according to one embodiment of the invention.

FIGS. 11A-11E are a perspective view and front, back, top, and bottomelevation views of an embodiment of the intermediate module of the drugdelivery device.

FIG. 12 is an exploded perspective view of the intermediate module ofthe drug delivery device, in accordance with one embodiment of theinvention.

FIG. 13 is a perspective view of an aerosol generator housing of theintermediate module of the drug delivery device, in accordance with anembodiment of the invention.

FIG. 14 is a cross-sectional view of one embodiment of the aerosolgenerator housing and a drug solution pool container of the intermediatemodule of the drug delivery device.

FIG. 15 is a cross-sectional view of the nebulizing device of FIG. 1B,taken along section line 15-15, according to an embodiment of theinvention.

FIG. 16 is a cross-sectional view of the nebulizing device of FIG. 1B,taken along cross-section line 16-16 of FIG. 1B, according to anembodiment of the invention.

FIG. 17 is an illustration of one embodiment of a method of forming andmounting a barrier within the intermediate module of the drug deliverydevice of the invention.

FIGS. 18A-18D are illustrations of front, side, and back plan views ofone embodiment of a mouthpiece module of the drug delivery device of theinvention.

FIGS. 19A and 19B are exploded perspective views of the mouthpiecemodule of the drug delivery device according to one embodiment of theinvention.

FIG. 20 is an illustration of the drug delivery device includinginterchangeable guide tubes in accordance with an embodiment of theinvention.

FIG. 21 is an illustration of the drug delivery device includinginterchangeable mouthpiece modules in accordance with an embodiment ofthe invention.

FIG. 22 is a cross-sectional view of the nebulizing device of FIG. 1B,taken along section line 22-22 of FIG. 1B, according to an embodiment ofthe invention.

FIG. 23 is a sectional view of the nebulizing device of FIG. 22, takenalong section line 23-23 of FIG. 22, in accordance with an embodiment ofthe invention.

FIG. 24 is a schematic representation of the circuitry of the drugdelivery device according to one embodiment of the invention.

FIG. 25 is an exemplary illustration of a method of control the drugdelivery device in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS OF THEINVENTION

FIG. 1A is a perspective view, FIG. 1B is a front elevational view, andFIG. 1C is a rear elevational view of an exemplary illustration of ahandheld nebulizing device 10 according to an embodiment of theinvention. The device 10 as illustrated includes a housing 12. While thehousing 12 of the present invention can be a unitary structure, in oneembodiment, and as illustrated, the housing is formed from threemodules, including a mouthpiece module 14, an intermediate module 16,and a base module 18 that can be coupled and decoupled from one another.As shown most clearly in the exploded perspective view of FIG. 2, thehousing 12 comprises a mouthpiece housing portion 20 for the mouthpiecemodule 14, an intermediate housing portion 22 for the intermediatemodule 16, and a base housing portion 24 for the base module 18.

As will be described in greater detail below, the mouthpiece module 14generally functions to deliver nebulized drug solution particles to auser through an outlet port 26. Atmospheric air is drawn into thehousing 12 through an air inlet port 28 formed on the rear of themouthpiece housing 20, as seen in FIG. 1C. Prior to delivery of thenebulized drug solution particles, the mouthpiece module has internalstructure that separates larger drug solution droplets from thenebulized particles that are delivered to the user and returns suchlarger droplets to a drug solution pool or reservoir, as will bedescribed.

The intermediate module 16 generally functions to contain a pool orreservoir of drug solution to be delivered to a user. The pool of drugsolution includes a metered dose of the drug solution provided by theuser to device 10. Intermediate module 16 also carries an aerosolgenerator that nebulizes the drug solution for delivery to the user.

The base module generally contains the device electronics and has acontrol interface 30, such as a manually operable button to enable theuser to activate the device 10.

As illustrated in the cross-section of FIG. 3, the nebulized particlesof the drug solution are formed in the device 10 from drug solution 116that sits upon an aerosol generator 118. Many different types of aerosolgenerators are known and may be used in certain embodiments of theinvention. In one embodiment, and as illustrated, the aerosol generator118 comprises an aerosol generator that generates acoustic waves withinthe drug solution 116. More specifically, the acoustic waves aretransmitted from aerosol generator 118 to drug solution 116 via a fluid120 between the drug solution 116 and aerosol generator 118. The drugsolution pool is sealed from the fluid 120 by a thin barrier 122, whichpermits acoustic waves to pass therethrough and be transmitted fromfluid 120 to drug solution 116.

In the embodiment illustrated in FIG. 3, the aerosol generator 118comprises a concave piezoelectric transducer with a silver electrode.The piezoelectric transducer 118 generates acoustic waves at a generatorfrequency, such as, in a non-limiting example, 2.5 MHz. The acousticwaves are focused by the concave configuration of the piezoelectrictransducer 118 at a focal point that is at a focal length from aerosolgenerator 118. Device 10 is arranged such that the focal point is withindrug solution 116. adjacent to or at the bottom of a guide tube 132, aswill be described.

In one embodiment, fluid 120 may primarily be comprised of water. Insome instances, a sterilant, such as alcohol, or another sterilant, maybe added to the fluid 120.

The aerosol generator may have additional or alternate structural andfunctional characteristics as described in International Application No.PCT/AU2003/001079 (International Publication Number WO 2004/017848),hereby incorporated by reference in its entirety. This invention alsocontemplates that any other aerosol generator present in the art couldbe used with the unique aspects of the present invention. For instance,the device may also be a traditional planar ultrasonic nebulizer, avibrating mesh nebulizer, a vibrating plate nebulizer, or anelectrospray nebulizer.

The drug solution present at the focal point of the acoustic waves willabsorb the ultrasonic energy from drug solution 116. That is, thefocused acoustic waves will generate a focused stream of drug solution,which the stream begins at a point that can also be considered thebeginning of the fountain. Towards the top of the stream or fountain128, the fountain sheds particles to aerosolize the drug solution. Someof the drug solution in the fountain 128 may not be nebulized, butrather form larger droplets of the drug solution that will be returnedto the drug solution 116 as described later.

In some embodiments of the invention, the nebulization of the drugsolution at fountain 128 may be enhanced when the focal point of theacoustic waves coincides (exactly or substantially) with a surface 130of the drug solution in drug solution 116. In such embodiments, thelevel of surface 130 may be controlled with some particularity toenhance the operation of fountain 128.

According to some embodiments of the invention, and as previouslymentioned, a guide tube 132 may be disposed within drug solution 116such that a first end 134 (the lower end in the figures) of guide tube132 may be positioned proximate to barrier 122, and a second end 136 ofguide tube 132 may extend out of drug solution 116. In such instances, aportion of the drug solution may be urged into the guide tube at thefirst end 134 resulting in the fountain 128 being formed at the secondend 136. The portion of the drug solution 116 within guide tube 132 ispropelled toward second end 136 of guide tube 132 by the ultrasonicenergy from the acoustic waves. At second end 136 of guide tube 132, theenergized drug solution stream exits the guide tube 132.

Continuing with reference to FIG. 3, nebulized particles pass throughdevice 10, from drug solution 116 to outlet port 26, via a separatorstructure 124, to the outlet 26. Separator structure 124 includes afirst region 138 and a second region 140. Second end 136 of guide tube132 extends into first region 138, and first region 138 receivesparticles of the drug solution therefrom. Second region 140 is inimmediate communication with outlet port 26. A wall 142 is formed inseparator structure 124 between first region 138 and second region 140.The drug solution is communicated between first region 138 and secondregion 140 via a passage 144 above wall 142. The various components ofseparator structure 124 may be arranged such that the nebulizedparticles may pass through to outlet port 26, while the larger dropletsof the drug solution may, due to size and/or weight, contact surfaces ofseparator structure 124, such as separator wall 142 or far wall 143 andcondense on the contacted surface. The drug solution that condenses onseparator structure 124 in second region 140 will be returned to drugsolution 116 via a drug solution return 146. Drug solution return 146may be disposed at a lower end of second region 140. The drug solutionthat condenses on separator structure surfaces in the first region 138will return to the drug solution 116 through a passage between anexterior surface of the guide tube 132 and surrounding walls of theseparator structure 142.

As described above and as illustrated in the figures (e.g., FIGS. 1C and3) the housing 12 of device 10 includes an inlet port 28. At inlet port28, intake gas is received by device 10. A delivery flow path may beestablished between inlet port 28 and the housing outlet port 26 thatdirects at least a portion of the intake gas such that the intake gasmotivates nebulized particles from fountain 128, through separatorstructure 124, to outlet port 26.

Referring again to FIG. 3, intake gas directed into separator structure124 via separator inlet 312 may flow past guide tube 132, throughpassage 144, and out of housing 12 at outlet port 26. The nebulizedparticles formed at fountain 128 may be motivated by the flow of theintake gas along the delivery flow path as the intake gas passesfountain 128 and proceeds toward outlet port 26. In an alternateembodiment, the intake gas may be provided by a self-contained gassource rather than by atmospheric air.

In some embodiments of the invention, activation of aerosol generator118 may generate sufficient energy to enable aerosol particles of thedrug solution to be propelled by fountain 128 into separator structure124, and out the outlet 26. As particles are propelled by fountain 128into separator structure 124, the atmosphere within separator structure124 may be disturbed such that air present at separator inlet 312 may bedrawn up into separator structure 124. That is, the movement of fountain128 may create a negative pressure within the housing 12, in a regionbetween the housing inlet port 28 and the separator inlet 312, and apositive pressure in the separator structure 124 above the fountain 128.Pulling air into separator structure 124 via separator inlet 312 mayinitiate the flow of intake gas along a delivery flow path, which willmotivate the nebulized particles formed at the fountain 128 towardoutlet port 26. Thus, the atmospheric disturbances caused by thenebulized particles from fountain 128 and the resulting flow of intakegas along the delivery flow may function in a cooperative manner to“drive” nebulized particles from fountain 128 to the user withoutrequiring additional moving parts such as fans, compressors, or thelike. Of course, such devices could be used to further increase the flowrate of nebulized drug should such a result is deemed desirable. Asdescribed later, a one-way valve, may optionally be disposed in thedelivery flow path, at a position between the inlet and outlet. Suchvalve would close to prevent gas that may be inadvertently exhaled by auser through the outlet from being expelled to atmosphere through theair intake 28, but be normally open to allow nebulized particles to passtherethrough to the outlet for user visibility. It has been found thatuser's of nebulizers take comfort in seeing the nebulized drug beingexhausted from the mouthpiece. This way they know that the device isworking properly and that their medication is being delivered therebyenhancing patient satisfaction and compliance. Use of a one-way valvethat is normally open permits a portion of the particles to be visuallyexpelled from the mouthpiece.

FIGS. 8, 9A-9D, and 10 are exemplary illustrations of the base module 18according to an embodiment of the invention. Base module 18 includes auser control interface 30 and control electronics 1010 contained in thebase module housing 24. Control interface 30 enables the user tointeract with control electronics 1010 to control device 10. In additionto providing a housing for control electronics 1010 and controlinterface 30, the base module housing 24 includes an intermediate moduleinterface 812 that enables base module 18 to be selectively coupled tointermediate module 16, as will be described later.

According to various embodiments of the invention, control interface 30enables the user to control various aspects of the operation of device10. Control interface 30 may include a knob, a button, a switch, akeypad, or other controls. Alternatively, the device could be controlledby an external memory encoded with instructions or wirelessly via an RFor Infrared signal. In a non-limiting example, control interface 30 mayinclude a power button 814 that may be depressed by the user. In oneembodiment, the power button 814 may be formed from silicon, or othermaterials such that power button may resiliently move inwardly whendepressed by the user, and return to its original configuration whenreleased such as an elastomeric membrane switch. Power button 814activates and de-activates the aerosol generator 118.

Referring to FIG. 10, control electronics 1010 are housed inside of basemodule housing 24. Control electronics 1010 may control various aspectsof operation of device 10. Control electronics 1010 may include, forinstance, hardware, software, firmware, or other electronics. Controlelectronics 1010 may include a power interface 916 that enables power tobe delivered from a power source to device 10. The power source mayinclude an AC source, such as a wall outlet or other AC sources, or a DCsource, such as one or more batteries, or other DC sources. In someembodiments, an internal power source may be provided within base modulehousing 24.

As shown in FIGS. 8 and 9C, the base module 18 has an intermediatemodule interface 812 that interfaces with a base module interface 112 ofintermediate module 16 (see FIGS. 11B and 11C) to selectively couplebase module 18 with intermediate module 16. Intermediate moduleinterface 812 includes a collar interface opening 816, a first slot 818,a second slot 820, and portion of a cup/base light pipe interface 722,as will be described later. As will also be described, and as shown inthe figures, base module interface 1112 forms the other portion of thecup/base light pipe interface 722.

The intermediate module interface 812 includes a metal electricalconnector receiver 824 and a collar receiver opening 826 formed in theupper surface 835 of the base module 18. Electrical connector receiver824 is electrically connected with the control electronics 1010 and isconnected to an electrical connector 1130 associated with the aerosolgenerator 118 in the intermediate module 16.

As shown in FIGS. 9C and 11E, collar receiver 826 receives a collar 1128associated with intermediate module 16. More specifically, collarreceiver opening 826 has a pair of enlarged opening portions 828, whichare arranged to receive ridges 1131 provided on the collar 1128. Due tothe enlarged profile of the collar 1128 at the ridges 1131, the collar1128 can only be inserted into, or rotated within, collar receiver 826when the ridges 1131 are positioned within enlarged portions 828. Inaddition, the end surfaces 829 at each end of the enlarged openingportions 828 serve as stop surfaces that may engage with the ridges 1131when the ridges are received in the opening portions 828 to limitrelative rotation between the base module 18 and intermediate module 16when they are coupled to one another.

The first slot 818 and second slot 820 in the intermediate moduleinterface 812 of base module housing 24 may include a first slot region830 and a second slot region 832, the second slot region 832 beingsmaller in width than first slot region 830. First slot 818 and secondslot 820 are adapted to receive tabbed protrusions 1132 and 1134 (seeFIG. 11B and 11C) associated with intermediate module 16 such that thetab ends 1155, 1156 included on the tabbed protrusions 1132, 1134,respectively, are first received into first slot regions 830, while theridges 1131 are aligned and inserted into the enlarged portions 828.Subsequently, the intermediate module housing 22 may be rotated withrespect to the base or control module housing, so that the tabbedprotrusions 1132, 1134 are slid to the narrower slot regions 832. As thetabbed protrusions 1132, 1134 on the intermediate module housing 22 areslid toward narrower slot regions 832 (e.g., moved clockwise as viewedin FIG. 9C into narrower regions 832), inwardly projecting tab ends1155, 1156 associated with the tabbed protrusions are positionedunderneath the upper wall region 835 of base module housing 24, so as tocouple and secure the base module housing 24 with the intermediatemodule housing 22. Subsequent rotation in a relative oppositiondirection can then decouple the base module housing 24 from theintermediate module housing 22.

In some instances, as illustrated in FIG. 10, a leaf spring 1011 may beprovided within each of first slot 818 and second slot 820. Leaf springs1011 may provide a bias to the tabbed protrusions to hold intermediatemodule 16 and base module 18 in the engaged position.

More particularly, leaf springs 1011 are provided at a floor of each offirst slot 818 and second slot 820 such that each of the leaf springs1011 form a first slot region floor 1013 within first slot region 830and a second slot region floor 1015 within second slot region 832,separated by a leaf spring ridge 1017. As is shown in FIG. 10, firstslot region floor 1013 provides a deeper floor surface than second slotregion floor 1015 within first slot 818 and second slot 820. Thus, astabbed protrusions 1132 and 1134 are introduced into first slot regions830, the tabbed protrusions 1132 and 1134 do not substantially contactfirst slot region floor 1013. However, as intermediate module 16 andbase module 18 are rotated with respect to each other to position tabbedprotrusions 1132 and 1134 into second slot regions 830, tabbedprotrusions 1132 and 1134 contact leaf spring ridges 1017 such thatinwardly projecting tab ends 1155 and 1156 are biased upwards into upperwall region 835, effectively inhibiting further rotation. By applyingsufficient force to overcome this bias applied by leaf spring ridges1017, tabbed protrusions 1132 and 1134 can be moved past leaf springridges 1017 and into second slot regions 830. When tabbed protrusions1132 and 1134 are positioned in second slot regions 830, second slotregion floors 1015, which are shallower that first slot region floors1013, contact inwardly projecting tab ends 1155 and 1156 to provide abias to tab ends 1155 and 1156 into upper wall region 835 that is not asstrong as the bias provided by leaf spring ridges 1017. In thisposition, leaf spring ridges 1017 act as retaining walls that securetabbed protrusions 1132 and 1134 in second slot regions 830.

Base module housing 24 houses various components of base module 18. Inone embodiment, as illustrated in FIG. 10, base module housing 24 isformed from a first base clamshell member 1016, a second base clamshellmember 1018, and a base member 1020. Base member 1020 includes aperipheral projecting tab 1022, while first base clamshell member 1016and second base clamshell member 1018 each include towards lower edgesthereof a base member receiving groove 1026 (not shown on clamshellmember 1016). Second base clamshell member 1018 also includes a pair ofbase clamshell grooves 1025 along opposite side edges thereof, whilefirst base clamshell member 1016 includes a pair of base clamshell tabs1024 along opposite side edges thereof. Base module housing 24 may beformed by joining first base clamshell member 1016, second baseclamshell member 1018, and base member 1020 such that base member tab1022 fits into base member grooves 1026, and base clamshell tabs 1024fit into base clamshell grooves 1025. First base clamshell member 1016,second base clamshell member 1018, and base member 1020 may be joinedvia one or more of a weld, an adhesive, a snap-fit, or other mechanismsfor securing separate members to each other. In one embodiment, the basemodule housing portions are all molded from ABS material.

In some embodiments of the invention, as shown in FIG. 9B, the exteriorof second base clamshell member 1018 may include one or more vents 910,a base grip section defining arcuate ridge 912, a base grip section 914,and a power source opening 916. Vents 910 enable atmospheric air outsideof base module housing 24 to be communicated to various componentswithin base module housing 24, such as control electronics 1010, forexample, for cooling thereof. The arcuate ridge 912 defines base gripsection 914. A separate base grip member 918 may be fixed to base gripsection 914 of the molded base module housing 24. Base grip member 918may be composed of a resilient or rubber-containing material to enhancea user's grip of base module 18. The grip 918 may be overmolded onto theplastic (e.g., ABS housing) shell 1018, for example, at region 914. Inother embodiments, the base grip member 918 may be separately formed andlater adhered to or otherwise affixed to the housing shell 1018.

The base member 1020 of the base or control module housing 24 may alsoinclude one or more vents 1028. The vents 1028 enable atmospheric airoutside of base module housing 24 to be communicated to variouscomponents within base module housing 24, such as control electronics1010, for example. The vents 1028 and 910 provide for cooling of thebase module electronics 1010.

FIGS. 11A-11E, 12, 13, and 14 are exemplary illustrations ofintermediate module 16 according to an embodiment of the invention.Intermediate module 16 includes the intermediate module housing 22, basemodule interface 1112, a mouthpiece module interface 1114, a drugsolution pool container 1206, and an aerosol generator housing 1208 thatcarries the previously described acoustic wave generator 118. In someembodiments, aerosol generator housing 1208 and/or drug solution poolcontainer 1206 are molded from polycarbonate or ABS, or a combinationthereof.

In an embodiment of the invention, as shown in FIG. 12, intermediatemodule housing 22 may include a first cup clamshell member 1210, and asecond cup clamshell member 1212. Intermediate module housing 22 housesvarious components of device 10 disposed in intermediate module 16.First cup clamshell member 1210 and second cup clamshell member 1212 mayinclude a plurality of clamshell support members 1214. Clamshell supportmembers 1214 provide structural support to first cup clamshell member1210 and second cup clamshell member 1212.

In one embodiment, intermediate module housing 22 may be formed byjoining first cup clamshell member 1210 and second cup clamshell member1212 around drug solution pool container 1206 and aerosol generatorhousing 1208. First cup clamshell member 1210 and second cup clamshellmember 1212 both have an upper edge defining an elongated curved groove1216. First cup clamshell member 1210 has vertically extending elongatedtabs 1218 along opposite ends thereof. Second cup clamshell member 1212has vertically extending elongated grooves 1220 along opposite endsthereof. Drug solution pool container 1206 includes a peripheral,radially outwardly extending flange 1222. First cup clamshell member1210 may be joined with second cup clamshell member 1212 around drugsolution pool container 1206 and aerosol generator housing 1208 byinserting cup clamshell member tabs 1218 into cup clamshell membergrooves 1220, and outwardly extending flange 1222 has a peripheral edgethat is received into drug solution pool housing grooves 1216. First cupclamshell housing portion 1210 and second cup clamshell member 1212 maybe joined around drug solution pool container 1206 and aerosol generatorhousing 1208 via a weld, an adhesive, a snap-fit, or other mechanismsfor securing separate members to each other. In one embodiment, thecomposition of intermediate module housing 22 may be ABS.

As shown in FIG. 11C, second cup clamshell housing portion 1212 mayinclude a plurality of projecting ridges 1122 formed in a square oralternatively shaped configuration defining a cup grip section 1124. Acup grip member 1126 may be adhered, overmolded, or otherwise fixed tocup grip section 1124. Cup grip member 1126 may be composed of a tackyor resilient material to enhance a user's grip of intermediate module16.

As can be appreciated from FIGS. 11B, 11C, and 13, the base moduleinterface 1112 of the intermediate module 16 enables intermediate module16 to be selectively coupled to base module 18 via intermediate moduleinterface 812 of the base module. The base module interface 1112,including tab extensions 1155, 1156, may be formed as an integrallymolded structure with aerosol generator housing 1208. Base moduleinterface 1112 mounts the previously mentioned electrical connector 130that is connected with connector 824 of the electronics 1010 carriedwithin base module 18.

As shown best in FIG. 13, aerosol generator housing 1208 may include aflange portion 1310 that provides on its lower side the base moduleinterface 1112. The aerosol generator housing 1208 may further include apedestal portion 1312, an aerosol generator seating portion 1314, and afluid filler opening 1328. Pedestal portion 1312 extends upwardly fromthe flange portion 1310. At an upper surface 1318 of pedestal portion1312, aerosol generator seating portion 1314 is provided for seating theaerosol generator 118. The aerosol generator 118 is peripherally sealedto the seating portion 1314 so that fluid 120 within the fluid chamber(as will be described) and sitting on the aerosol generator 118 does notleak into cavity 1320 formed between the aerosol generator 118 andaerosol generator housing 1208. Cavity 1320 has a connector opening 1322that receives the electrical connector 1130 that enables power and/orcontrol signals to be transmitted to aerosol generator 118 from controlelectronics 1010.

As best seen in FIG. 14, the aerosol drug solution pool container 1206has a lower skirt portion 1409 that cooperates with the aerosolgenerator housing 1208 and aerosol generator to define a sealed chamber1416 for containing fluid 120. The pool container 1206 further includesan upper cup region 1411 for containing the drug solution 116. The cupregion 1411 is separated from the chamber 1416 by a separating wall1413. The separating wall 1413 has an opening 1412 formed therethrough.The opening 1412 is sealed by the previously described barrier 122,which is disposed between the fluid 120 and drug solution 116. Drugsolution pool container 1206 may be joined with aerosol generatorhousing 1208 by having the lower skirt 1409 secured to an outer edge1326 of pedestal portion 1312 via a weld, an adhesive, or othermechanisms for securing one component to another.

Fluid 120 may be introduced into fluid chamber 1416 via chamber opening1328 (see FIG. 13). Chamber opening 1328 is provided at upper surface1318 of pedestal portion 1312, and may be accessible at a side ofaerosol generator member 1208 opposite from fluid chamber 1416(illustrated, for example, in FIG. 11E). Subsequent to the introductionof fluid 120 into fluid chamber 1416, chamber opening 1328 may be sealedby being plugged with a suitable material.

In one embodiment of the invention, as seen most clearly in FIGS. 13, 15and 16, a structure 1418 is disposed within fluid chamber 1416 and is incontact with the fluid 120. This resilient structure may be reduced involume so as to reduce the amount of space it occupies in the chamber1416 when the volume of fluid 120 increases. In the embodimentillustrated, the structure 1418 comprises an expansion protectionbladder composed of a deformable resilient material to accommodateexpansions in the volume of fluid 120, and thereby protect othercomponents from potential damage due to changes in the volume. Forinstance, aerosol generator 118, barrier 122, may potentially be subjectto damage in the event that ambient temperature surrounding device 10 islow enough to cause a fluid temperature of fluid 120 to approach orreach freezing. Or, fluid 120 may also expand in the event that thetemperature of fluid 120 rises. In the event of such expansion of fluid120, the resilient structure will reduce in volume to accommodate theincreased volume of the fluid. This, for example, may prevent crackingof the fluid chamber 1416.

FIGS. 15 and 16 are illustrations of how the structure 1418 operatesaccording to one example. In FIG. 15, the fluid temperature of fluid 120may be at or near normal room temperature. FIG. 16 illustrates how theexpansion protection bladder may deform to accommodate an expansion offluid 120. Expansion protection bladder is composed of a deformablematerial, such as, for instance, silicon, or other deformable materials.The bladder has an opening 1419 peripherally sealed to an opening in theupper surface 1318 of pedestal 1312. The opening 1419 leads into aninternal space in the bladder that is exposed to atmospheric pressure.Structure 1418 may be vented to the atmosphere via a passage 1420 thatleads to an open space 1421 in the housing. The space 1421 is not sealedand this is allowed to bleed air and receive air to and from theatmosphere. Because the amount of air displaced is small and only needsto be done over a long period of time, there is no need for a large ventin the intermediate module housing 22, as the slow permeation of air toand from region 1421 is sufficient.

It is contemplated that the structure 1418 can be formed from differentmaterials, or from a plurality of different members. For example, thestructure can be made from an elastomeric material, such as silicone oranother elastomeric material, a sponge material, a closed cell foammaterial, or other materials. In another embodiment, the structure 1418may include a rigid structure that is biased into the chamber 1416 by aspring (e.g., a coil spring or leaf spring) or other resilient member.The rigid structure would form a moving seal with the chamber 1416 andtake up more or less of the chamber volume based on the fluid volume asdescribed above. In this instance, the spring constant of the springmember would be tuned for optimal resistance. Where a bladder isemployed, the spring constant is engineered with several variables inmind, such as the durometer and thickness of the bladder material.

In another contemplated embodiment, the structure comprises a resilientmaterial part of the skirt wall 1409 of the chamber 1416. For example,the skirt wall 1416 may have a window formed therein, and a thin sheetof resilient material may cover and seal the window. Increasing volumeof the fluid 120 in this embodiment would cause the resilient materialto bulge outwardly.

The barrier 122 provided between fluid 120 and drug solution 116 mayinclude a material that meets various design criteria. Design criteriamay, include, for example, a prescribed thickness, an elasticity, adurability at high temperatures, an acoustic wave transmission property,or other criteria. This construction enables acoustic waves to betransmitted through the barrier 122, from fluid 120 to drug solution116.

As seen in FIG. 14, the barrier 122 is mounted over barrier opening 1412by being mounted to barrier mounting surface 1414 formed on an undersideof separating wall 1413.

FIG. 17 is an exemplary illustration of a method of forming and mountingbarrier 122 according to an embodiment of the invention. At an operation1710, a first barrier part 1712 is formed, for example, by being stampedfrom a roll of material. First barrier part 1712 may be stamped into agenerally circular shape, or may be of another shape. First barrier part1712 in one embodiment is of a thickness that is less than or equal to0.0005 inches and greater than 0.0001 inches. First barrier part 1712may be composed or polyetheretherketone (PEEK), or other similarmaterials.

At an operation 1714, a second barrier part 1716 is formed, again bybeing stamped from a sheet or roll of material. Second barrier part 1716includes an opening 1718 generally defining a central portion of barrier122. Second barrier part 1716 may be of a second barrier thicknessgreater than the first barrier thickness. For example, the secondbarrier thickness may be approximately ten times greater than the firstbarrier thickness. Second barrier part 1716 may be composed ofpolyetheretherketone (PEEK), or other materials.

The method includes an operation 1720, at which the first barrier part1712 is sealed to second barrier part 1716 to form barrier 122. Secondbarrier part 1716 is sealed to first barrier part 1712 at a peripheralportion of first barrier part 1712 to form a peripheral portion 1722 ofbarrier 122. Peripheral portion 1722 defines a central portion 1724 (seeoperation 1726) of barrier 122 with a smaller thickness than a thicknessof peripheral portion 1722. In a non-limiting example, first barrierpart 1712 and second barrier part 1716 may be sealed via an ultrasonicweld, or otherwise sealed.

At an operation 1726, a plurality of holes 1728 are formed in theperipheral portion 1722 of barrier 122. In one embodiment, holes 1728may be die cut in peripheral portion 1722 of barrier 122.

The method may include an operation 1730, in which barrier mountingsurface 1414 of the drug solution container 1206 is coated with one ormore sealants 1732.

For example, barrier mounting surface 1414 may be coated with asilicon-based adhesive, or other sealants.

The mounting surface 1414 includes a plurality of integrally formedprojections 1734. At an operation 1736, peripheral portion 1722 ofbarrier 122 is mounted to barrier mounting surface 1414. Mountingbarrier 122 to barrier mounting surface 1414 positions central portion1724 of barrier 122 over barrier opening 1412. At operation 1736,projections 1734 are received within holes 1728 of barrier 122.

At operation 1738, projections 1734 are deformed. Deforming projections1734 functions to clamp peripheral portion 1722 of barrier 122 tobarrier mounting surface 1414.

Because the barrier 122 has a substantially thicker peripheral portionthan central portion, it can be more easily secured or clamped to thebarrier mounting surface 1414 in comparison with a barrier that wouldhave a periphery with the same thickness as the central portion. Inaddition, the thickness of the central portion of the barrier 122 can beengineered for optimal performance without concern that it may be toothin for optimal securement to the mounting surface 1414. In otherwords, in one embodiment of the present invention, the thickness of thecentral portion of the barrier 122 independent of the thickness of theperipheral portion, enables each portion to have an optimized thicknessto support its associated functionality.

In another embodiment, the first barrier part 1722 and the secondbarrier part 1716 are molded as a one-piece integral structure, with theperipheral part being of a greater thickness than the central part. Thegreater thickness of the peripheral part is better adapted forsecurement to the barrier mounting surface, while the thinner centralpart is better adapted for transmitting acoustic waves.

In one embodiment, the separating wall 1413 between the chamber 1416 andthe cup region 1411 has an upper angled floor surface 1422 on which thedrug solution 116 sits. The angled floor surface 1422 is essentiallydisposed one side of the opening 1412 formed in separating wall 1413.More specifically, an angled floor surface 1422 is disposed towards asame side of device 10 as outlet port 26. The floor surface 1422 on theopposite side of opening 1412 is essentially of a stepped configuration.Opposite angled floor section 1422 and stepped floor section 1424 areshaped to drain toward barrier 122. The sloping configuration of floorsurface 1422 is such that it continues to drain the drug solution 116 tothe barrier 122 when the drug solution 116 is depleted and as thehousing 12 may be tilted by a user during operation.

As best seen in FIGS. 11D, 11A and 12, mouthpiece module interface 1114is provided by front slot 1138 and one or more rear slots 1140 formed inperipheral flange 1222 of the pool container 1206.

FIGS. 18A-18C and 19 are exemplary illustrations of the mouthpiecemodule 14 according to an embodiment of the invention. Nebulizedparticles of the drug solution held in intermediate module 16 may becommunicated to the user via mouthpiece module 14. Mouthpiece module 14includes a mouthpiece housing 20, an inner mouthpiece member 1912, andthe guide tube 132. Guide tube 132 is securely held by inner mouthpiecemember 1912, as described later, and the inner mouthpiece member 1912 isdisposed inside of mouthpiece housing 20, as will also be described. Themouthpiece housing 20, in one embodiment, is molded from a polypropylenematerial, although other suitable materials can also be used. The guidetube 132, in one embodiment, is made from a corrosion resistant metal,such as stainless steel.

As shown in FIG. 19, mouthpiece housing 20 includes a first housingmember 1914 and a second housing member 1916. Second housing member 1916has an upper peripheral lip provided with a protruding ridge 1918. Firsthousing member 1914 and second housing member 1916 may be joined suchthat mouthpiece housing ridge 1918 is received by one or more ridgereceiving members (not shown) disposed at a peripheral lower edge offirst housing member 1914. A mechanism for securing first housing member1914 and second housing member 1916 to each other to form mouthpiecehousing 20 may comprise a weld, an adhesive, a snap-fit betweenmouthpiece housing ridge 1918 and the ridge receiving members, or othermechanisms for securing components to each other.

The first housing member 1914 includes the outlet port 26. Outlet port26 is disposed toward a side of device 10 to enable a user to positiontheir mouth on mouthpiece housing 20 around outlet port 26 to receivethe nebulized particles of the drug solution from device 10.

As best seen in FIG. 18A, the first housing member 1914 includes a firstpair of internal alignment ridges 1920. As best seen in FIG. 19, secondhousing member 1916 includes a second pair of alignment ridges 1922.When first housing member 1914 and second housing member 1916 arejoined, the first pair of housing alignment ridges 1920 are aligned andfunctionally joined with the second pair of housing alignment ridges1922 to form a channel into which inner mouthpiece member 1912 may beinserted when inner mouthpiece member 1912 is disposed within mouthpiecehousing 20. This channel acts as a guide passage for guiding nebulizedparticles of the drug solution from separator outlet 148 to outlet port26 and also filters the particles.

As best seen in FIGS. 18B and 18D, the rear of second housing member1916 includes inlet port 28 and a finger rest 1810. At inlet port 28,intake gas is introduced into mouthpiece housing 20. Finger rest 1810 isa protrusion that extends outwardly from an outer surface of secondhousing member 1916. The finger rest is adapted to engage a finger (orhand) of the user as the user holds device 10 to receive nebulizedparticles of drug solution therefrom. Finger rest 1810 is disposedproximate to and beneath the inlet port 28, so that the finger or handof the user holding device 10 is inhibited from inadvertently slidingover (and thus blocking) inlet port 28 during use.

As best seen in FIGS. 18A and 18D, the front of second housing member1916 includes a convex-shaped, downwardly extended portion 1812.Extended portion 1812 is configured such that when mouthpiece module 14is selectively coupled to intermediate module 16, extended portion 1812fits into recessed portion 1120 in the intermediate module housing 22(see FIG. 1B). Extended portion 1812 includes a depressible surface 1816that may be depressed by the user to selectively decouple mouthpiecemodule 14 from intermediate module 16, as will be described below withgreater particularity. Reinforcement ridges 1924 inside the secondhousing member 1916 (see FIG. 19A) provide reinforcement to secondhousing member 1916 at a side opposite extended portion 1812. Thereinforcement of second housing member 1916 provided by reinforcementridges 1924 enables the user to squeeze second housing member 1916 toflex depressible surface 1816 without simultaneously deforming theopposite side of second housing member 1916. This reduces the amount offorce the user must apply in squeezing second housing member 1916 toadequately deform extended portion 1812 for coupling or uncouplingmodules 14 and 16 because all (or substantially all) of the forceapplied by the user is used to deform depressible surface 1816, and notboth depressible surface 1816 and the opposite of second housing member1916.

As shown in FIG. 18C, inner mouthpiece member retaining tabs 1814 areprovided at opposing sides of mouthpiece housing 20. Inner mouthpieceretaining tabs 1814 secure inner mouthpiece member 1912 withinmouthpiece housing 20. Specifically, the flexing capability of thehousing member 1916 allows a substantially flat base portion 1917 of theinner mouthpiece member 1912 to ride over the retaining tabs 1814 and beretained thereby. That is, when the inner mouthpiece member 1912 isinserted upwardly into the outer mouthpiece housing 20, the outer edges1919 of the base portion 1917 are able to ride over the tabs 1814 and beretained thereby. In an alternate embodiment, the inner mouthpiecemember can be secured to mouthpiece housing 20 by a snap-fit, a weld, anadhesive bond, or other mechanisms for securing housing parts to eachother.

In one embodiment of the invention, the inner mouthpiece member 1912comprises two molded portions that are subsequently secured to oneanother. For example, in FIG. 19A, a first structure member 1926 and asecond structure member 1928 is shown. First structure member 1926includes one or more grooves (not shown) disposed at a side of firststructure member 1926 to be joined to second structure member 1928.Second structure member 1928 may include one or more projections 1930disposed at a side of second structure member 1928 to be joined to firststructure member 1926. First structure member 1926 and second structuremember 1928 may be joined to form inner mouthpiece member 1912 such thatprojections 1930 may be received by the grooves. First structure member1926 and second structure member 1928 may be secured to each other byone or more mechanisms for securing components to each other, such as,for example, a weld, an adhesive bond, a snap-fit, or other mechanismsfor securing components to each other.

Inner mouthpiece member 1912 includes a stop member 1932, a guide tubecollar 1820, a baffle 310, the previously described base portion 1917,and separator structure 124. The base portion 1917 forms part of a cupinterface portion 1818 that enables mouthpiece module 14 to beselectively coupled to intermediate module 16. In one embodiment, thecup interface portion 1818 includes a biased barbed tab 1822, and one ormore rigid barbed tabs 1824. Biased barbed tab 1822 and rigid barbedtabs 1824 are disposed on cup interface portion 1818 such that biasedbarbed tab 1822 may engage front slot 1138 (see FIG. 11D) associatedwith intermediate module 16 and rigid barbed tabs 1824 engage rear slots1140 associated with intermediate module 16 to selectively couplemouthpiece module 14 to intermediate module 16.

Barbed tabs 1822 and 1824 are engaged with slots 1138 and 1140 byinserting rigid barbed tabs 1824 into rear slots 1140 and pivotingmouthpiece module 14 with respect to intermediate module 16 (or viceversa), about a fulcrum formed by the engagement between rigid barbedtabs 1824 and rear slots 1140, until biased barbed tab 1822 approachesfront slot 1138. As biased barbed tab 1822 approaches front slot 1138, aforce may be applied to biased barbed tab 1822 at an outer side ofbiased barbed tab 1822 that deforms biased barbed tab 1822 to enablebiased barbed tab 1822 to engage front slot 1138. After biased barbedtab 1822 engages front slot 1138, a stop 1825 provided on the tab 1822to impede further pivoting of mouthpiece module 14, at which point theforce may be released, thereby effectively coupling mouthpiece module 14to intermediate module 16 as the barbs associated with barbed tabs 1822and 1824 engage mouthpiece interface portion 1222 in which slots 1138and 1140 are formed. To uncouple mouthpiece module 14 from intermediatemodule 16, a force can be applied to biased barbed tab 1822 at the outerside of biased barbed tab 1822 that deforms biased barbed tab 1822 suchthat the barb associated therewith may be disengaged from slot 1138,enabling mouthpiece module 14 to be pivoted with respect to intermediatemodule 16. Biased barbed tab 1822 may be disposed on cup interfaceportion 1818 such that the user may apply a force to biased barbed tab1822 by depressing depressible surface 1816 of extended portion 1812associated with mouthpiece housing 20.

As shown in FIG. 19A, stop member 1932 may be formed proximate toseparator structure 124 on a same side of separator structure as inletport 28. Stop member 1932 serves to engage an inner surface 1916 of theouter mouthpiece housing portion (see FIG. 22), as inner mouthpiecemember 1912 is positioned and/or retained in mouthpiece housing 20. Thislimits upward movement of inner mouthpiece member 1912 into mouthpiecehousing 20.

Intake gas introduced into mouthpiece housing 20 through air intake vent28 is separated by baffle 310. Specifically, referring to FIG. 4A, whena user inhales through outlet port 26, a first portion of the intake gasfrom the atmosphere flows above baffle 310, directly to outlet port 26.A second portion of the intake gas flows below baffle 310 to be directedinto the drug solution pool cup 1411 and through the separator structure124 for delivery to the user. The intake gas is divided into the firstportion and the second portion according to several considerations. Forexample, since the first portion of the intake gas provided directlyfrom air intake vent 18 outlet port 20 travels over a less restrictedpath than the second portion of the intake gas that is directed into thedrug solution pool cup 1411 and through the separator structure 124, thedivision of the intake gas between these two paths reduces an amount ofsuction that must be applied by the user in inhaling the nebulizedparticles. Another consideration includes avoiding a provision of anexcessive amount of the intake gas into the drug solution pool cup 1411and through the separator structure 124, which may interfere with theformation and delivery of the nebulized particles by creating a gas flowwith too high a flow rate. The intake gas may be divided according toother considerations. In one embodiment, approximately 60% of the intakegas may be included in the first portion and the remaining approximately40% of the intake gas may be included in the second portion, or theintake gas may be otherwise divided.

After the intake gas (e.g., from atmosphere) that is used for drugdelivery passes below baffle 310, it passes through an opening 1826formed in inner mouthpiece base portion 1917 (see FIG. 18C) and into thepool cup region 1411. The intake gas then travels back through baseportion 1917, a central opening 1829 formed therein, and leading toseparator inlet 312. The air intake then travels through separatorregions 130 and 140 (see FIG. 3) and carries with it nebulized particlesthrough outlet 26.

As discussed previously, the device 10 may optionally be provided with aone-way valve 314 within the drug delivery flow path. As can be seen inFIGS. 18C and 19A, in the present embodiment, the one-way valve 314 isdisposed within the opening 1826. Valve tabs 1934 formed on the baseregion 1917 may interface with one or more peripheral grooves 1936formed on one-way valve 314 such that one-way valve 314 may be securedinto valve opening 1826. Thus, intake air that is drawn beneath thebaffle 310 must pass through the valve 314 prior to entering into thedrug solution pool cup and the separator inlet 312.

In one embodiment, one-way valve 314 is a passive valve. At a default or“normal” position, one-way valve 314 is open, enabling intake gas topass freely therethrough from inlet port 28 to separator inlet 312. Thisnormally open position enables nebulized particles generated at fountain128 to be motivated to outlet port 26 when the device 10 is powered on.As a result, the open default position of one-way valve 314 enablesdevice 10 to produce a visible aerosol at outlet port 26 when device 10is activated without the user engaging device 10 at outlet port 26 toinhale. The presence, or absence, of the visible aerosol at outlet port26 enables the user to determine whether device 10 is operating prior toengaging the mouth at outlet port 26. Being able to visualize theaerosol prior to inhalation may provide comfort to the user that thedevice 10 is functioning properly.

In one embodiment, one-way valve 314 will close when gas is introducedto device 10 at outlet port 26. This may occur, for example, when theuser inadvertently exhales into device 10. Closing one-way valve 314when gas is introduced to device 10 at outlet port 26 will inhibit gasfrom flowing in a reverse direction along the delivery flow path, whichwould force the drug solution that may be airborne within device 10 tobe expelled via inlet port 28.

In one embodiment, the one-way valve 314 has a valve body defining anaperture 316, and a valve flap 318, integrally connected (by beingintegrally molded) with the body. The connection may be in the form of a“living hinge.” Under typical operating circumstances, valve flap 318may permit intake gas to flow through valve aperture 316 from inlet port28 to separator inlet 312. As is illustrated in FIG. 4B, when gas isintroduced into device 10 at outlet port 26, a resulting flow of gas anddrug solution of sufficient velocity from separator inlet 312 to inletport 28 will cause valve flap 318 to close, sealing (or substantiallysealing) the delivery flow path. Sealing the delivery flow path in thismanner will cause the gas introduced to housing 12 at outlet port 26 toremain above the inner housing base 1917 and to flow out of device 10via inlet port 28 in a flow path that is reverse of the direct flowpath.

It should be appreciated that any normally open one-way valve can beused. In one embodiment, a ball and spring type check valve may be used.In one embodiment, the one way valve may be electrically operated, suchas by a solenoid. In such an embodiment, the one way valve may benormally closed, and may be opened when the user is engaging outlet port26 to inhale. For example, the electrically operated valve may be openedbased on an automated detection of engagement of outlet port 26 by theuser, or the valve may be opened based on a user control.

As can be appreciated from FIGS. 18D and 19A, the guide tube 132 isfixed to guide tube collar 1820. Guide tube collar 1820 is supported byone or more collar struts 1828. Collar struts 1828 extend from separatorstructure 124 at separator inlet 312 to guide tube collar 1820. Thecentral opening 1829 in the inner housing base member is of a largerdiameter than the guide tube 132. Thus the drug delivery flow path fromthe drug solution cup 1411 passes through the central opening along apassage that is between the edge 2009 surrounding the opening 1829 andthe exterior surface of guide tube 132. From the central opening 1829,the drug delivery flow path is able to enter into the separator inlet312.

According to one embodiment of the invention, an inner diameter of guidetube 132 may be varied to provide control over one or more aspects ofthe nebulization of the drug solution. For instance, by varying theinner diameter of guide tube 132, a nebulized particle size delivered tothe user, a flow rate of the drug solution delivered to the user, orother aspects of the nebulization may be controlled. In a non-limitingexample, guide tube 132 may include an inner diameter of between 2 mmand 3 mm, with smaller inner diameters producing smaller nebulizedparticles and/or a lower flow rate, and larger inner diameters producinglarger nebulized particles and/or a higher flow rate.

For example, in FIG. 20 the first guide tube 132, of a first innerdiameter, may be selectively uncoupled from guide tube collar 1820. Thismay enable a second guide tube 2012, of a relatively smaller innerdiameter, to be coupled to guide tube collar 1820 in place of firstguide tube 2010. In this embodiment, the outer diameter of the guidetubes 132 and 2012 are the same, thus allowing each to be affixed to thesame guide tube collar 1820. As a separate example, as illustrated byway of example in FIG. 21, a first mouthpiece module 2110 may include afirst guide tube 2112, of a first inner diameter. First mouthpiecemodule 2110 may be selectively uncoupled from intermediate module 16 toenable a second mouthpiece module 2114, including a second guide tube2116, of a smaller inner diameter to be selectively coupled tointermediate module 16, thereby varying the inner diameter of the guidetube employed in device 10. In yet a third embodiment, the mouthpieceouter housing 20 may be used with different inner mouthpiece housingshaving associated the guide tube of different inner diameter.

In some embodiments, the flow rate and/or the size of the nebulizedparticles is adapted to the lung size of the user. This is because theflow rate and/or the size of the nebulized particles impact the locationin the lungs of the user where the drug solution will be delivered. Forexample, in delivering the drug solution to the same region of two setsof lungs associated with two separate users with different lung sizes,the drug must travel different distances. In the embodiments shown inFIGS. 20 and 21, the guide tubes may be interchanged to optimizedelivery of a single drug solution to the two separate users. In theseinstances, first mouthpiece module 2110, and second mouthpiece module2114 may include other customizations for the two separate users.

In a non-limiting example, illustrated by FIG. 21, first guide tube 2112may be adapted for delivering the drug solution to a user with a smallerlung size, such as the lung size of a child, than second guide tube2116, which may be adapted to the lung size of an adult. In thisexample, mouthpiece modules 2110 and 2114 may be further customized tothe intended users by including a smaller first outlet port 2118 onfirst mouthpiece module 2110 than a second outlet port 2120 on secondmouthpiece module 2114.

As mentioned previously, and as can be appreciated from FIGS. 2, 8,9A-9C, and 11A-E, modules 14, 16, and 18 may be selectively coupled toand decoupled from each other. That is, the module housing 20, theintermediate module housing 22, and the base module housing 24 areprovided with interengaging structure that enables these housingportions to be coupled and decoupled, as will be described later ingreater detail. Moreover, as shown in FIG. 7, in one embodiment, device10 optionally includes an interlock detection system 710 that ensuresthat modules 14, 16, and 18 are satisfactorily coupled to each otherprior to activation of device 10. In one embodiment, the interlocksystem 710 may include a signal transmitter carried by the housing, asignal receiver carried by the housing, and a conduit that transmits asignal from the transmitter to the receiver. When one of the modules isseparated from the adjoining module or misaligned to prevent the signalfrom being transmitted from the transmitter to the receiver, the aerosolgenerator is disabled when the signal is prevented from beingtransmitted from the transmitter to the receiver. For example, thepresence or absence of the signal at the receiver may be transmitted tothe control electronics, which may disable the aerosol generator, ortransmit a deactivation control to the aerosol generator, in the absenceof the signal.

In the illustrated embodiment, the signal transmitter is an infrared(IR) source 712, the receiver is an IR detector 714, and the conduit isan internally reflecting light pipe 716, 718 with mouthpiece surface 720as will be described. Of course a variety of other signaltransmitters/receivers could be used in accordance with the presentinvention that operate at different frequencies outside the Infraredband such as visible light or RF. In fact a multitude of differentsignals across the electromagnetic spectrum could be used withoutdeparting from the unique aspects of the present invention. The source712 is disposed in the base module 18 and emits a signal along adetection path to the detector 714. The signal travels through basemodule light pipe 716 to a cup light pipe/base light pipe interface 722,disposed at the juncture between the base module 18 and intermediatemodule 16. When the intermediate module housing 22 is coupled to thebase module housing 18, the cup/base light pipe interface 722 are joinedin abutting relation, thus permitting radiation to pass from base lightpipe 716 to cup light pipe 718. The signal passes through cup light pipe718 to a mouthpiece/cup light pipe interface 724 carried by themouthpiece housing 20. At mouthpiece/cup light pipe interface 724, themouthpiece module 14 is provided with a reflective surface 720. Thus,when the mouthpiece housing 20 is coupled with the cup housing 22, theIR signal emitted from cup light pipe 718 is reflected by reflectivemouthpiece surface 720 and retraces the optical path back to base module18, where detector 714 receives the reflected radiation. If the modules14, 16, and 18 are not satisfactorily coupled, the detection path willbe broken, and the radiation will not be returned to the detector 714.Based on the absence of or insufficiency of radiation at detector 714,interlock system 710 will disable activation of device 10. For example,in one embodiment, the detector 714 is functionally coupled with thedevice control electronics, which disables the device 10 by preventingthe aerosol generator (e.g., piezoelectric transducer) 118 from beingactivated when the signal conduit is broken.

In this embodiment, the signal may be constantly transmitted or thesignal could be intermittently transmitted. The detector would beprogrammed to prevent drug deliver, until the anticipated signal isreceived. In the event that the detector is programmed to permit drugdelivery upon sensing a constantly transmitting signal, there is thepotential that the detector could be fooled by exposing the detector toan appropriate light source. To address this possibility, the inventorscontemplated that an intermittent signal could be used. Use of anintermittent signal could reduce the potential for the signal detectorbeing fooled by other light sources. In this embodiment, the signaldetector would need to detect a signal having a particular signalpattern. Of course, the signal could be a simple on and off having aparticular frequency; however, a variety of other signal pulse patternscould be utilized without departing from the spirit or scope of thepresent invention.

In another contemplated embodiment, the transmitter sends a simpleelectrical signal that is transmitted through an electrical conduit fromthe base module 18, through the intermediate module 16 to the mouthpiecemodule 14, where it may be detected by a signal receiver, or where it isthen returned to a signal receiver in the base module 18. The signalreceiver functionally cooperates with the device control electronics todisable the aerosol generator 118 when the signal is prevented fromreaching the signal receiver. In such an embodiment, the respectiveinterfaces between modules 14, 16, and 18 may comprise simple electricalcontacts that are broken when a module is disengaged. A variety ofdifferent switches could be used to create a signal interrupter thateither makes or breaks contacts when the modules are disassembled ormisaligned. The switch could be a mechanical switch using electricalcontacts between the modules, or a push button switch that is actuatedduring assembly. Alternatively, the switch could utilize a magneticfield for actuation rather than mechanical contacts such as a reedswitch or a magnet with a corresponding magnetic sensor such as ahall-effect sensor.

In another embodiment, a wireless proximity detector can by employed. Insuch an embodiment, a wireless transmitter sends a signal that may bereceived by a wireless receiver in the mouthpiece module. In thisinstance, the conduit may be considered the space through which thewireless signals are transmitted. When the receiver in mouthpiecehousing is farther than a threshold distance from the transmitter, theconduit is broken as the signals can no longer be received by thereceiver, and the control electronics will disable the aerosol generator118.

One benefit to the interlock arrangement is when the base module 18 iscoupled with the intermediate module 16, but before the mouthpiecemodule 14 is coupled with the intermediate module 16, the user cannotinadvertently activate the aerosol generator without the mouthpiecemodule 14 in place. By contrast, it should also be appreciated that whenthe mouthpiece module 14 is coupled with the intermediate module 16, butthe base module 18 is disconnected from the intermediate module 16,inadvertent activation of aerosol generator 1118 would have no effect onthe drug solution because the control electronics of the base module 18and power source would not be connected with the aerosol generator inthe intermediate module 16. It can be appreciated, therefore, that in anembodiment that employs the mouthpiece module, and a signal module thatcontains all of the control electronics of the base module 18 and theaerosol generator of the drug solution pool of the intermediate module,then only an interlock detection between the mouthpiece module 14 andthe rest of the assembly can be employed.

It should be appreciated that many of the principles and featuresdescribed herein can be used in an embodiment of the present inventionthat does not employ the guide tube 132. In such a system, most of thevolume of the drug solution within the device 10 is contained in areservoir that feeds the drug solution to the pool region that rests onthe aerosol generator 118 as the drug solution 116 becomes depleted. Avalve system, such as a float valve, can be used to regulate or controldistribution of the drug solution from the reservoir to the aerosolgenerator 118.

More particularly, in one embodiment illustrated in FIGS. 5 and 6, drugreservoir 210 may provide the drug solution to drug solution 116 viafill channel 212 to replenish the drug solution when the level of uppersurface 130 of the drug solution drops due to nebulization, or otherfactors, thereby maintaining the level of upper surface 130 of the drugsolution 116 at or proximate to the focal point of the acoustic wavesgenerated by aerosol generator 118.

A float valve 214 may be positioned at fill channel opening 212 in drugsolution 116 such that when the level of upper surface 130 rises, float214, which is buoyant in the drug solution, rises up to block the drugsolution from flowing into drug solution 116 from fill channel 212.However, when the level of upper surface 130 begins to drop, float valve214 falls away from fill channel opening 212, thereby enabling the drugsolution in fill channel 212 to flow into drug solution 116 until thelevel of upper surface 130 rises to a point where float 214 again blocksfill channel opening 212. Float valve 214 may include an angled floatsurface 218. Angled float surface 218 may interface with an angleddevice surface 220 to bias float valve 214 against fill channel opening212 as float valve 214 rises. In one embodiment, float valve 214 iscomposed of a closed cell foam material.

The large droplets of the drug solution formed at fountain 128 areseparated from the nebulized particles of the drug solution formed atfountain 128 by the separator structure 124. Subsequent to separation,the large droplets are returned to drug solution reservoir 210 via drugsolution return 146. In one embodiment, drug solution reservoir 110 maybe annular.

In some embodiments of the invention, separator structure 124 mayprovide a drug delivery path from fountain 128 to outlet port 26 for thenebulized particles formed at fountain 128. As the nebulized particlestravel along the drug delivery path, separator structure 124 providessurfaces that separate nebulized particles formed at fountain 128 fromthe larger droplets formed by the drug solution propelled out of drugsolution 116 prior to delivery of the nebulized particles to the user.Subsequent to separation from the nebulized particles, the largerdroplets are returned to drug solution 116.

This arrangement is disclosed more fully in co-pending U.S. PatentApplication Ser. No. 60/659,919, entitled NEBULIZING DRUG DELIVERYDEVICE WITH INCREASED FLOW RATE, filed on even date herewith and herebyincorporated by reference in its entirety.

FIGS. 22 and 23 illustrate an optional embodiment of device 10 thatincludes a drug solution detection system 2210. Drug solution detectionsystem 2210 detects if the amount of drug solution 116 falls below athreshold level based on detection of an AC electrical signal detectedin drug solution 116. Drug solution detection system may include a probe2212, and a signal lead 2214.

Probe 2212 is positioned to detect the AC signal generated by the ACapplied to the aerosol generator. Of course the signal could begenerated by various other devices. In other words, the drug solutionitself may act as a conduit for the AC signal that conducts the ACsignal to probe 2212. When the upper surface 130 of the drug solution116 falls below the threshold level, the drug solution will no longeract be able to deliver the AC signal to probe 2212. Although probe 2212is illustrated as being disposed within drug solution 116, detecting theAC signal directly, in other embodiments, probe 2212 may be disposed incontact with an outer surface of a wall of drug solution pool cup 1411and may detect the AC signal capacitively through the wall. The ACsignal (or lack thereof) detected by probe 2212 may be relayed tocontrol electronics 1010 via signal lead 2214. At base module interface1112, signal lead includes a lead connector 2310 disposed within tabbedextrusion 1132 that transmits the AC signal to control electronics vialeaf spring 1011.

In one embodiment, when the AC signal is not detected, controlelectronics 1011 may automatically deactivate device 10. For example,aerosol generator 118 may be deactivated. Or, control electronics 1011may activate an alert, such as, for example, a visual or audibleindicia, that may warn the user that upper level 130 of the drugsolution may have dropped below the threshold level.

The threshold level as contemplated herein can be virtually “empty”.However, it may be desirable for the threshold level to be some drugsolution volume above empty, to allow the user sufficient warning thatthe drug solution is near depletion. In addition, when the drug solutionvolume reaches below a certain level, its thermal mass also drops belowa threshold that may make it more susceptible to temperature changes inthe environment or due to components within the device itself. Suchtemperature changes may be undesirable, as it may alter theeffectiveness of certain drug solutions. In one non-limiting example, itmay be desirable in some embodiments of the present invention to providethe device 10 with a heater that heats the drug solution 1116. Such aheating arrangement may be desirable to lower the viscosity of the drugsolution pool, particularly when using a drug solution of a highviscosity. Such a heater may be provided in contact with the drugsolution 116 itself, or surrounding the drug solution cup region 1411,as described in previously mentioned co-pending U.S. Patent ApplicationSer. No. 60/659,919, filed on even date herewith and entitled NEBULIZINGDRUG DELIVERY DEVICE WITH INCREASED FLOW RATE, and which is incorporatedby reference in its entirety. In the event that the amount of drugsolution drops below a threshold level, the thermal mass of the drugsolution 116 may be subject to over heating. This may be prevented bydisabling the aerosol generator 118 through use of the controlelectronics 1011 when the amount of drug solution drops below athreshold level as described above.

In another embodiment, it is contemplated two different drug solutionlevels may be detected. In such a system, a first low level is detectedand provides either an audible or visual alarm to the user. This mayprompt the user to refill the device 10 with drug solution. At thisfirst low level point, however, the drug solution may not besufficiently low to cause device 10 to be disabled, and the aerosolgenerator will continue to function. At a second low level point (e.g.,when the drug solution 116 is of a less than desirable thermal mass) thesystem control electronics 1011 will then disable the aerosol generator.In such a dual level detection arrangement, it is contemplated that thecontrol electronics can sense two different current levels transmittedthrough the drug solution 116, as the current level decreases with theincreased resistance due to drug solution depletion. In anotherembodiment, two or more different probes are provided for detecting thetwo or more different drug levels.

It should also be appreciated that many of the principles of the presentinvention can be employed without a level detector, or with a known,conventional level detector.

In addition to detecting drug level, probe 2212 could be used for avariety of other unique purposes. First, probe 2212 could be used todetect if cup region 1411 has been breached (including barrier 122 orseparating wall 1413). If breached, probe 2212 would be able to detectthe change in the signal. Secondly, probe 2212 could be used as a sensorto detect the operation of aerosol generator 118. For instance, in theevent that the aerosol generator is a piezoelectric device, it has beenfound that the amplitude of the detected AC shifts as the frequencyapplied to the piezoelectric device changes. It is preferred to operatethe device at its resonant frequency which may vary from component tocomponent. The resonant frequency corresponds with the maximum amplitudeof the AC signal. Therefore, the resonant frequency can be identified bylocating the maximum amplitude. In essence, this process is tuning thedevice. In the preferred embodiment, the resonant frequency occurssomewhere between 2.3 to 2.7 MHz. To find the optimum operatingfrequency of the device 10, the detected AC may be analyzed as the AC iscycled from frequency to frequency.

Alternatively, rather than using probe 2212, the operation of thepiezoelectric device can be detected without probe 2212 by measuring thecurrent drawn by the piezoelectric device. The current drawn by thepiezoelectric device increases as the piezoelectric device approachesits resonant frequency. Once again, the frequency of the AC may becycled from frequency to frequency to determine the frequency thatresults in the maximum current draw. In the preferred embodiment, themaximum frequency occurs somewhere between 2.3 to 2.7 MHz. Although thisprocess could be performed at anytime, the inventors presently considerit to be desirable to perform this diagnostic at startup each time thedevice is turned on. Once the optimum frequency for the device isdetermined, this value may be stored in memory in electronics 1010.

It should also be appreciated that many of the principles of the presentinvention can be applied to a dual system that employs more than oneaerosol generator 118. This may be useful again where a high viscositydrug solution is being used, in order to increase the amount of drugthat can be delivered. This dual arrangement is also disclosed in theaforementioned Application 60/659,919 that has been incorporated hereinby reference.

It should also be appreciated that many of the principles of the presentinvention can be applied to a system designed for implementation withina ventilator circuit. This may be useful again where high viscosity drugsolution is being used, in order to increase the amount of drug that canbe delivered. Such an embodiment is disclosed in the co-pending U.S.Patent Application Ser. No. 60/659,782, entitled NEBULIZING DRUGDELIVERY DEVICE FOR VENTILATOR, filed on an even date herewith, andwhich is incorporated by reference herein, in its entirety.

Referring to FIG. 24, an exemplary illustration of an electricalschematic representation of device 10 is provided. Control electronics1010 are operatively linked with various components of device 10, suchas, for example, control interface 30, a power source 2410 (this mayinclude the power source coupled to device 10 via power interface 910,and/or an internal power source), aerosol generator 118, level detectionsystem 2210, interlock system 710, and/or other components. The variouscomponents transmit signals to control electronics 1010 and/or receivecontrol signals from control electronics 1010.

FIG. 25 illustrates an exemplary method of controlling a handheldnebulizing drug delivery device. Various electronic components withinthe device may initiate and/or execute some or all of the operations ofthe method.

The method includes an operation 2510 at which an activation command isreceived. The activation command may be initiated by a user that isusing the device via, for example, a control interface, or may beautomatically generated.

At an operation 2512, a determination is made as to whether one or moredevice modules included in the device are properly coupled. For example,a signal, emitted by a signal transmitter, may be received at a signalreceiver. If the signal receiver does not receive the signal, the devicemodules are not properly coupled, and the method proceeds to anoperation 2514. At operation 2514, an aerosol generator is deactivated.This includes both maintaining the current operating state of theaerosol generator if the aerosol generator is currently deactivated, anddeactivating a currently activated aerosol generator. The deactivationof the aerosol generator prevents the device from generating, orattempting to generate, nebulized particles of drug solution fordelivery to the user.

If, at operation 2516, the determination is made that the device modulesare properly coupled based on, for example, reception of the signal bythe signal receiver, then the method proceeds to an operation 2516. Atoperation 2516, the aerosol generator is activated. This includes bothmaintaining the current operating state of the aerosol generator if theaerosol generator is currently activated, and activating a currentlydeactivated aerosol generator. The activation of the aerosol generatorenables the device to generate nebulized particles of drug solution fordelivery to the user.

The method includes an operation 2518, at which a determination is madeas to whether a threshold amount of drug solution is present in thedevice for nebulization. In some instances, this determination includesmonitoring a signal of a probe associated with a pool of drug solutionheld within the device. The probe receives the signal from the aerosolgenerator through the pool of drug solution so long as the pool of drugsolution includes an amount of the drug solution greater than thethreshold amount, but does not receive the signal once the amount of thedrug solution in the pool of drug solution falls below the thresholdamount. If the signal is not received by the probe, signifying that theamount of the drug solution in the pool of drug solution is below thethreshold amount, the method proceeds to operation 2514.

If, at operation 2518, the signal is received by the probe, signifyingthat the amount of the drug solution in the pool of drug solution isabove the threshold amount, the method proceeds to an operation 2520. Atoperation 2520, a determination is made as to whether a deactivationcommand has been received. A deactivation command may be initiated by auser that is using the device via the control interface. If adeactivation command has been received, the method proceeds to operation2514.

If, at operation 2520, a deactivation command has not been received, themethod proceeds to operation 2522. At operation 2522, a determination ismade as to whether the aerosol generator has been activated for a timethat exceeds a time out period. The time out period may be automaticallydetermined, or may set by the user. The time out period may be set toprotect various electronic components within the device from excessivestress, dose of the drug, or according to other considerations. If thetime out period has been exceeded, the method proceeds to operation2514. If the time out period has not been exceeded, the method returnsto operation 2512.

It can thus be appreciated that embodiments of the present inventionhave now been fully and effectively accomplished. The foregoingembodiments have been provided to illustrate the structural andfunctional principles of the present invention, and are not intended tobe limiting. To the contrary, the present invention is intended toencompass all modifications, alterations, and substitutions within thespirit and scope of the appended claims.

Although the invention has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred embodiments, it is to be understood that suchdetail is solely for that purpose and that the invention is not limitedto the disclosed embodiments, but, on the contrary, is intended to covermodifications and equivalent arrangements that are within the spirit andscope of the appended claims.

1. A nebulizing drug delivery device, comprising: a housing, the housingcomprising a mouthpiece module, an intermediate module, and a basemodule, wherein the mouthpiece module is configured to be releasablycoupled with the intermediate module, and wherein the base module isconfigured to be releasably coupled with the intermediate module; anaerosol generator disposed within the housing; a signal transmittercarried by the housing; a signal receiver carried by the housing; and asignal path configured to transmit a signal from the transmitter to thereceiver, wherein the signal path is disrupted by the mouthpiece modulebeing decoupled from the intermediate module; wherein the signal path isdisrupted by the base module being decoupled from the intermediatemodule, wherein disruption of the signal path prevents any signal frombeing transmitted from the transmitter to the receiver via the signalpath, and wherein disruption of the signal path disables the aerosolgenerator.
 2. A nebulizing device according to claim 1, wherein the basemodule carries electronics for operating the aerosol generator.
 3. Anebulizing device according to claim 1, wherein the transmitter is an IRsignal transmitter and the receiver is an IR signal receiver, and thesignal path comprises a light pipe for carrying the IR signal.
 4. Anebulizing device according to claim 3, wherein the light pipe isdisconnected from another component of the signal path when either ofthe mouth piece and base modules is disconnected from the intermediatemodule.
 5. A nebulizing drug delivery device, comprising: a housing, thehousing comprising a mouthpiece module, an intermediate module, and abase module, wherein the mouthpiece module is configured to bereleasably coupled with the intermediate module, and wherein the basemodule is configured to be releasably coupled with the intermediatemodule; an aerosol generator disposed in the intermediate module thatgenerates acoustic waves in a drug solution that is provided within thehousing, the acoustic waves in the drug solution operating to formnebulized particles from the drug solution that can be communicated to auser through an outlet of the mouthpiece module; a signal transmittercarried by the housing; a signal receiver carried by the housing; and asignal path configured to transmit a signal from the transmitter to thereceiver, wherein the signal path is disrupted by the mouthpiece modulebeing misaligned with the intermediate module; wherein the signal pathis disrupted by the base module being misaligned with the intermediatemodule, wherein disruption of the signal path prevents any signal frombeing transmitted from the transmitter to the receiver via the signalpath, and wherein disruption of the signal path disables the aerosolgenerator.
 6. A nebulizing device according to claim 5, wherein the basemodule carries electronics for operating the aerosol generator.
 7. Anebulizing device according to claim 5, wherein the transmitter is an IRsignal transmitter and the receiver is an IR signal receiver, and thesignal path comprises a light pipe for carrying the IR signal.
 8. Anebulizing device according to claim 7, wherein the light pipe isdisconnected from another component of the signal path when one of themodules is disconnected from the other modules.
 9. A nebulizing devicecomprising: a housing, the housing comprising a first housing assemblyand a second housing assembly that are configured to releasably coupledwith each other, the first housing assembly carrying an aerosolgenerator and control electronics that operate the aerosol generator togenerate acoustic waves within a drug solution provided into the firsthousing assembly, the acoustic waves in the drug solution operating toform nebulized particles from the drug solution, the second housingassembly including an outlet through which the nebulized particles arecommunicated to a user; a signal transmitter carried by the housing; asignal receiver carried by the housing; and a signal path through whicha signal is transmitted from the transmitter to the receiver, the signalpath comprising a first component carried by the first housing assemblyand a second component carried by the second housing assembly, thesignal path being disrupted when one of the housing assemblies ismisaligned or decoupled from the other of the housing assemblies,wherein disruption of the signal path prevents the signal from beingtransmitted from the transmitter to the receiver, and wherein theaerosol generator is disabled by disruption of the signal path.
 10. Anebulizing device according to claim 9, wherein the first housingassembly comprises a plurality of separable components.
 11. A nebulizingdevice according to claim 10, wherein the plurality of separablecomponents comprises a cup component in which the drug solution isprovided that includes the aerosol generator, and a base component thatincludes the control electronics.
 12. A nebulizing device according toclaim 9, wherein the transmitter is an IR signal transmitter and thereceiver is an IR signal receiver, and the signal path comprises a lightpipe for carrying the IR signal.
 13. A nebulizing device according toclaim 12, wherein the light pipe is disconnected from another componentof the signal path when one of the housing assemblies is disconnectedfrom the other housing assembly.
 14. A nebulizing device according toclaim 13, wherein the light pipe is disconnected when one of theplurality of separable components is disconnected from others of theplurality of separable components.